Use of silanes as concrete additives



United States Patent 3,190,762 USE OF SILANES AS CONCRETE ADD Barber C. Carlson and Robert C. Hartlein, Midland,

Mich., assignors to Dow Corning Corporation, Midland, 5

Mich., a corporation of Michigan No Drawing. Filed Jan. 28, 1963, Ser 0. 254,402

54 Claims. (Cl. 106-90) settingtimes of concrete, can be increasWn 5 silanes are admixed therewith. Apple-air; have also discovered that the durability of concrete can be improved when certain silanes are admixed therewith.

Furthermore, applicants have found that both comressive strength and the air volume of cqncrete are rilf g0 creased when" certain silanes are admixed therewith in thea'mounts specified below. This discovery was most unexpected because, heretofore, airzentrainingagents have dgreased the compressive strength o f concrete by about 10 fie'icnt. Applicants method not'only increases the air volume and compressive strength, but also increased the durability of concrete.

It is an object of this invention to provide a concrete with improved compressive strength. It is a further object to provide a concrete having both improved compressive strength and increased air content. It is also an object to provide concrete having increased durability.

It is a further object to provide a method for reducing the maximum temperatures produced by hydration during EXAMINER 3,190,762 Patented June 22, 1965 the curing of concrete, thereby allowing more flexibility in pouring large masses of concrete. Another object is to provide a method for increasing the set times of concrete, thereby increasing the flexibility in the pouring of concrete.

This invention relates to an improved concrete and its method of manufacture, said concrete having admixed therewith from 0. to 3 percent by weight of a silane of the formula Zsfl fimerein Z is a member selected fro'mm'consisting of hydrocarbon groups and substituted hydrocarbon groups in which the substituent is bonded to the silicon atom through at least one carbon atom, and R is selected from the group consisting of alkyl radicals of from 1 to 3 inclusive carbon atoms, -CH CH 0R"', and -CH CH OH in which R'" is an aliphatic hydrocarbon radical of l to 3 inclusive carbon atoms.

The products of this invention are prepared by merely mixing the silane with the concrete and then allowing the concrete to set. The mixing can be done at any stage of the preparation of the concrete. For example, the silane can bejhmgwixed with Portland cement to produce a dry mix. This dry mix can then be used along with aggregate and water to prepare the concrete. Alternatively, the silanes can be added after the other ingredients of the concrete have been mixed.

For the purpose of this invention Z can be any hydrocarbon or any substituted hydrocarbon radical. tive of the hydrocarbon groups that are represented by Z in the formula above are the aliphatic and cyclo-aliphatic hydrocarbon groups containing from 1 to 18 carbon atoms, aryl groups containing from 6 to 18 carbon atoms, aralkyl groups and alkaryl groups. More specifically Z can be:

--(CH:):CECH -cH=cHoH=cH,

-CH; --crr=cm -cH.oHcH. -o,n. -on.cn=om 413G --O4H| Q -omcrn -CoH1: C (CHa)= r -c.H.1 Q :)r

, (CHI): -01@H=1 Q-omcm -cn=oncn,cn=on,

Illustra- Preferably the hydrocarbon group is a phenyl group or Th h an aliphatic hydrocarbon radical of from 1 to 18 inclusive 6 groups S own an 11 ustrauve of the subsmuted carbon atoms hydrocarbon groups that are represented by Z --011 CONHQ @Il (0 CH3):

R can be an alkyl radical of from 1 to 3 inclusive carbon atoms, such as methyl, ethyl or isopropyl. R can also be -CH CH OCH CH CH OH, --CH CH OCH(CH Suitable examples of hydrocarbon-substituted silanes which are operative in this invention include methyltrimethoxysilane, propyltrimethoxysilane, phenyltrimethoxysilane, dodecyltrimethoxysilane, octadecyltrimethoxysilane, CH Si(OCH CH OCH CH Si(OCH CH OH) amyltrimethoxysilane, ethyltrimethoxysilane, vinyltrimethoxysilane and methyltriisopropoxysilane. Suitable examples of substituted hydrocarbon silanes which are operative herein include gamma-mercaptopropyltrimethoxysilane, omega-hydroxyhexytriisopropoxysilane, deltacyanobutyltriethoxysilane, gamma-aminoamyltriethoxy 2 5 2 2 )3 2)3 z s) s s) and omega aminooctadecyl tris (,8 hydroxyethoxy)silane. These silanes are well known materials and may be prepared by any of the methods commonly known in the art.

Although the invention is not so limited, it is thought that the silanes hydrolyze and condense to form siloxanes when they are mixed with concrete.

Although the over-all range for the addition of these materials to concrete is from 0.05 to 3 percent by weight (based on the weight of Portland cement in the concrete),

different effects occur within this range depending upon the type and amount of silane used. All of the previously described silanes retard set times throughout this range. In general, the higher the concentration, the more the set time is retarded. The combination of increased air content and compressive strength is obtained only within certain ranges depending upon the silane used. With the phenyl silanes, both of these effects occur within the range from 0.1 to 0.75 percent by weight. When the propylsilanes are used, the range producing both effects is from 0.3 to 1 percent by weight. When the ethyl and vinyl silanes are used, the range producing both effects is from 1.5 to 3 percent by weight. The ethoxy and propoxy silanes do not increase the air content of concrete, but do increase set time and compressive strength. Both eliects are obtained with the other silanes at concentrations from 0.5 to 3 percent by weight.

When the upper limit for these silanes are exceeded, the compressive strengths fall off markedly and the air content of the concrete is raised excessively, e.g., above 7 percent by volume. It is preferable to have an air content between 3 and 7 percent by volume, however, smaller or larger amounts of air can be present. If small quantities of these silanes are used, the air content of the concrete is not appreciably increased. When one is only interested in raising compressive strength of concrete without increasing the air content, amounts smaller than the (CHa) SCH2G O O CaHs above limits can be used. For example, the compressive strength of concrete is increased by 0.05 percent by weight of CH Si(OCH When one is only interested in increasing the set time of the concrete without increasing the air content or compressive strength, 0.3 percent by weight of the cyclohexyltrimethoxysilane can be employed. If desired, two or more of the alkoxysilanes can be employed in any one concrete mix. However, in doing so, the effects produced at various concentrations should be kept in mind.

The term concrete" as employed herein has reference to any material which is based upon Portland cement as a cementing material and which contains an aggregate. The aggregate can be sand, gravel or other solid materials which are normally employed in concrete. The concrete of this invention can also contain any of the additives which are normally added to concrete in order to improve setting characteristics, or to prevent freezing of the concrete in cold weather.

Since most of these silanes, at certain concentrations, increase the air content of concrete, it is not necessary to add air entraining agents. However, when it is desirable to add smaller quantities of these silanes or to use the ethoxy or propoxy silanes, air entraining agents can be advantageously employed in conjunction with the silanes to increase the air content. Examples of commercially available air entraining agents that can be employed in conjunction with the silanes are Vinsol NVX, Darex ABA and Airalon, N-Tair, Ad-Aire, Sulfonate WS, D-4O and D-60, Foamasol and morpholine oleate. Vinsol NVX is the sodium soap of Vinsol resin made by treating the resin with caustic soda: Vinsol resin is a hard, brittle, dark-colored, thermoplastic resin which consists substantially of a petroleum-hydrocarbon insoluble fraction of a coal-tar hydrocarbon extract of pine wood. It contains phenol, aldehyde and ether groups. Darex AEA is a harmless, dark brown, water-soluble triethanolamine salt of a sulphonated hydrocarbon with a viscosity approximately that of water. Airalon consists substantially of hydroaromatic and fatty carboxylic acids being derived from an alkaline process of paper manufacture and neutralized to make a water-soluble soap. The acids, if rcgenerated from the soap, have an acid number of -160. Ad-Aire is a neutralized Vinsol resin liquid. Sulfonate WS is a water-soluble petroleum sodium sulfonate. It consists of 25 percent sodium sulfonate, 15 percent mineral oil, 0.4 percent sodium carboxylate, 0.4 percent free NaOH, 9 percent inorganic salts and the balance water. D-40 and D-60 are dry surface active agents containing approximately 40 percent and 60 percent, respectively, of sodium alkyl benzene sulfonate. Foamasol is a salt of an alkylnaphthalene sulfonic acid and protein materials. Other air entraining agents that can be employed in making concrete are well known and will be obvious to those skilled in the art.

The concrete of this invention can be employed for any structural or non-structural use and can be reinforced and/or prestressed. The concrete of this invention is especially useful when employed as road and bridge surfaces. The compressive strength and the air content are The initial and increased (with the exception of the ethoxy and propoxy T able ll silanes), by the addition of these silanes at certain concentrations to concrete. The compressive strength is in- Wt Time arse hours creased at these and even lower concentrations. Material percent n The setting time of the concrete is increased by the Initial Final addition of these silanes. This factor should be taken into consideration when a fast setting time is required. NO additive 2 5 3 5 These silanes can be used to specifically increase the cH sigoci'l'gia'" 1.25 315 715 setting time of concrete. This can be used to advantage gzgg gg gz when attempting to pour large unified masses, such as 11 3; cn cfi '''fi fijjj 1: 12 bridges. The amount of silane to be added will depend gfi l 2 5 1(OCH3)3..-.- 1.25 3.75 6.75 upon the setting time increase desired. The phenyl- 15 CH CHSi(OCH;) 1.25 3.75 s alkoxysilanes (preferably in amounts from 0.1 to 0.35 per- 8 8} g 5 cent by weight) are especially eflective as set retardants. C3H7Si(OC H; .I 011 4.25 5:75 The maximum temperatures produced by hydration gffgggg hgfgflfz: if 75 during curing are reduced when these silanes are admixed 0H5$1 0CH20H20 c1193---- 011 3.5 6 with concrete. This is of value when pouring large struc- CHaSKOCHtCmOH): tures. The amount of water required in the concrete mix is reduced by admixing these silanes with the concrete. The addition of these silanes to concrete increases the EXAMPLE 3 durability of the concrete. This is particularly true of The concrete employed in this example was prepared concrete (e.g. concrete bridges that is sub ected to numer- 25' by mixing one part by weight of Portland cement, 2 parts 0115 freezethiiw cycles by weight fine sand and sufiicient water to increase the The following examples are illustrative only and S o flow to 100 percent. The following alkoxysilanes were not be constmfed as hmltmg the ")ventlon Whlch 15 Prop mixed with the concrete after the water had been added X Set forth m the pp clalms- O to the sand and cement. The percentages of alkoxy sil- EXAMPLE 1 3 anes added are based on the weight of Portland cement in 1 d 1 d the concrete. In each case the compressive strength and .concrete aye f g e was g g the percentages of air contained in the concrete was by mixing parts y t 0 an cament an higher than when the concrete contained no additive. parts by weight crushed limestone aggregate, 44.6 parts by weight sand particle size and smaller) and 9.6 1.25 percent of C H9Si(OcH3)3 parts by weight water. 'In each case the silane was added 125 percent of C5HHSi(OCH3)3 after a portion of the water had been mixed with the 25 percent of C2H5Si(OcH3)3 other ingredients. After further mixing, the concrete was 2.5 percent of CHFCHSI(OCH3)3 poured into 4" by 8" cylinders and allowed to set. The 125 percent of Cl2H25Si(OCH3)3 silanes used and the properties of these samples are set 40 forth in Table I. The percentages of silanes added are EXAMPLE 4 based on the weight of Portland cement in the concrete. The percentages of air in the concrete are based on the The concrete employed in this example was prepared volume of concrete and this percentage is determined in by mixing one part by Weight f Portland cement, 3 parts accqlidance f ASTM In each by weight fine sand and sufficient water to increase the addition of a silane to the concrete ncreased the durab lity how to 100 Percent The alkoxysilahes were mixed with of the concrfle 0Ver cfmcrete comalmng addltlve concrete after the water had been added to the sand and or only an air entraining agent. The compressive strength cement The percentages f alkoxy silanes added are Was determlned after 7 and 28 Y based on the weight of Portland cement in the concrete. The quantity of water required with each material is Table I stated in the table.

O tr h, Wt. Percent p. s.i. Table III Material percent air cone.

7 days 28 days Compressive Wt. Water strength p.s.i. Material percent in mi. No additive 1. 9 3 ,925 cone. Commercial air entraining 7 days 28 days 75 5. 3 4,210 No additive 525 1,350 2,310 0. 35 5.2 5,590 cmsuocnp. 0.1 525 1,680 2,555 1.25 41 5,455 cmsuooHm 0.3 500 1,975 2,555 i. 25 5.8 5,165 OHQSKO CH5); 0. 7 500 2,615 2,815 1. 25 22 5,125 1.25 2.3 5,550 5 2522 0155 510 51295 EXAMPLE 5 0.85 4.1 5,585 2.3 ,815 An improved concrete is obtained when the following materials are added to the concrete formulation of EX- EXAMPLE 2 ample The concrete employed in this example was prepared 1.25 percent by weight C H11Si(OCH3)3 by mixing one part by weight Portland cement and 2.5 1.25 percent by weight C H Si(OCH parts by weight fine sand and sufficient water to increase 0.2 percent by weight C H Si(OCH the flow to 100 percent. The set times were determined 3 percent by weight C H Si(OCH by using the Gillmore needle at 100 F. and 100 percent 2 percent by weight CHF-CHCH Si(OCH 9 EXAMPLE 6 her of cycles from three bars run. At a 5 percent weight loss the test bar is considered to have failed.

The various cements were also tested and rated visually as to the degree of surface scaling. The top formed bar surface was rated on a scale of from 1 (very slight scaling-excellent surface condition) to 5 (severe scaling). If this surface reaches a scale rating of 5 between 100 to 150 cycles, its scaling resistance is rated as poor (P); 150 to 200 cycles, fair (F); 200 to 250 cycles, good (G); 250 or more cycles, very good (VG). The results are given in the following table:

Table IV Set time Compressive Dura- Wt. Percent (hours) strength (p.s.1.) bility Scaling Material percent air in 10% resistconc. NaCl ance Initial Final 7 days 28 days Darex AEA 133 4. 7 5. 5 7. 5 2,820 3,195 210 P Vinsol NVX 02 5. 5 5. 5 7. 5 2,990 3,570 219 P C H5Si(OCHa)3. .3 6 22 24 4,256 5,903 1 32A VG C H Si0 CHa)a. 3 5. 6 22 24 3 ,463 4,816 335 VG 05H i 0 3):..- 3 5. 4 15. 59 23. 5 4 ,450 6 ,410 265 G CsH5Si(O CHah.-- .5 6 28 4,350 4,626 490 VG '(O .5 6.8 28 30 3,520 5,553 292 VG 5 5. 9 28 30 4 ,133 5 ,433 385 VG 3 5. 5 21 24 3 ,455 380 H;N(CH2)zNH(CHr)aSi(OCH3); .3 2.5 21 24 3,943 H;N(CH2)2NH(CH2)3S1(OCH .3 2.7 21 24 4,790 HzN(CH2)2NH(CH2)3Si(OCH3): .3 3.9 21 24 4,296 H N(CH2)zNH(CH1)3Si(O CH3): .3 2.7 21 24 4,713 HzN(CH2)1NH(CH2)s i(O CH3): .3 3.4 21 24 4,440 H2N(CH2):NH(CH:)3S1(OCH M .5 3.8

CHz-CHCH1O(CH2)3S1(OCH3)3 .3 2.8 11 12.75 3,520 4,136 230 VG CH2-CHCH20(CH2)3S1(OCH3)3 .3 6.5 11 12. 75 3,183 4,176 362 F FsGCHzCHzSi(OCHa)a----- .3 4 14.29 22 4,243 6,193 232 G giga g si ggng .2 8.4 15. 29 31.15 3,980 241 VG 2 2 2 7 3 I Morphoiine oieate.--- .os 5 21 24 3 4 VG 1 Only one bar run. 2 Only two bars run.

The Darex ABA and the Vinsol NVX were included for purpose of comparison.

EXAMPLE 7 The concrete employed in this example was prepared as in Example 6 except that cement from a different lot,

durability. The durability reported is the average numwas used.

Table V Set time Compressive Dura- Wt. Percent (hours) strength (p.s.i.) biiity 1 Scaling Material percent air in 10% resisteonc. N e01 anee Initial Final 7 days 28 days Dare. 12 5. 2 6. 25 8. 5 2,670 3 ,240 275 F H2 2)2NH(CH2)aSi(OCH3); .2 2. 2 3,716 5,293 H1N(CH2)2NH(CH Si(OCHM.-- .3 4.8 21 24 4,073 4,966 274 HzC=CECHa)COO(CHg) SiOOHa) .1 4.3 3,523 4,296 H2G=C CHa)GOO(CHz)aSi OCHa) .3 13.5 1&5 22 3,840 5,420 283 VG glg-(CH )CNHHC(%1I) C 1E%i S 1](3O)CHs)i --u .3 4 11 12. 3,340 5 ,443 G a 1 a a i j m5 4. 0 5.190

I All results for one her only.

1 1 EXAMPLE 8 The concrete employed in this example was prepared as in Example 6 except that cement from a different lot was 12 a )a z)2( 2)5 3 4 c11 sucn scn cu used. 5

Table VI Set time Compressive Dura- Wt. Percent (hours) strength (p.s.i.) bility Material percent air in cone. NaCl Initial Final 7 days 28 days Darex AEA. 133 5.15 5. 38 7. 38 2,063 2, 919 164 CH;CH4Si(O CH3): 3 10 27 43 3, 020 295 C H C H4Si O CH 3 5. 8 10 13.5 (CHghCHCdLSKOCHa); 3 15.5 12 228 Si(0 CH1): 3 6. 2 15. 5 17. 5 2, 090 3, 080 165 CHClcHCH2si(OCH3)3---- 3 4. 2 8 11 2,320 3, 360 (CH3)2N(CHz)aSi(O CH5) 3 15. 5 15 23. 5 2, 980 288 C1(CHz)aSi(0CH 3 2.6 10.5 13 3,660 4, 640 HOC HACHzhSKOCHa): 3 -2 11 19 2,500 3,190

HgN(CH3)3NHCH1CHCH2Si(O CH3): 3 6- 2 22 24 3, 290 5, 22 227 EXAMPLE 9 (6) (CH O) Si(CH P(O) (C2H5) (C H The concrete employed in this example was prepared by mixing 24.8 pounds of Portland cement, 89.25 pounds of crushed limestone aggregate, 64.25 pounds of sand (MW particle size and smaller) and about 13.75 pounds of water. The air entraining agent (control) or silane was added after a portion of the water had been mixed with the other ingredients. I

(7) (CH :CHOCH CH O) Si(CH Si(CH EXAMPLE 12 When the following silanes are employed in the concrete of Example 6 an improved concrete is obtained:

(1) (CH O) Si(CH NI-lCH CH N1-ICH CH COOCH (2) (CH O) Si(CH NHCH CH N(CH CH COOCH Table VII Set time Compressive Wt. Percent (hours) strength (p.s.i.) Material percent air cone.

Initial Final 7 days 28 days Da -ex AFA .133 5.4 5.25 7.25 1,933 3,020 reassess-6H3 a 3-2 rgnisiw cfinljf .31:1 I3 312 22 3,716 5,336 C H Si(8 811 1 33.. 10 12. 75 14. 75 C H Si( 3 a M orpholine oleate 11 8 16 18 626 676 EXAMPLE 10 EXAMPLE 11 When the following silanes are employed in the concrete of Example 7 an improved concrete is obtained:

(3 (CH O Si (CH NHCH CH NHCH CH COOCH CH OH (4) (CH O) Si (CH NHCH CH NH HOOCCH In the following three examples various cements were also tested and rated visually as to the degree of surface scaling. The method employed was similar to the one employed by the Portland Cement Association and the US. Bureau of Public Roads in their freeze-thaw work. This method is described by Verbeck et al. in the Highway Research Board Bulletin (1957), pages 1 to 13. Procedure 2 of the test was employed with the following exceptions. The specimens used in the scaling test were slabs 2" in depth and 5" x 9" in area. The slabs were cast in oiled wood molds and a 2 percent sodium chloride solution was used instead of water. Also a freeze-thaw cycle of -17 F. to 70 F. was employed. The slabs were rated on a scale of from 1 to 5. A rating of 1 equals very slight scaling, 2 equals slight scaling, 3 equals moderate scaling, 4 equals severe scaling and 5 equals failure of 13 i the slab. A plus attached to the rating indicates that the scaling was localized. A rating of 2+ is considered better than a rating of 2, 3+ better than 3, etc.

EXAMPLE 13 That which is claimed is:

1. A method which comprises incorporating in a concrete mix from 0.05 to 3 percent by weight based on the weight of the Portland cement in the concrete of a silane of the formula ZSi(OR') wherein Z is a member selected from the group consisting of hydrocarbon groups and substituted hydrocarbon groups in which the substituent is bonded to the silicon atom through at least one carbon atom, and R is selected from the group consisting of alkyl radicals of from 1 to 3 inclusive carbon atoms, CH CH OR' and CH CH OH where R is an aliphatic hydrocarbon radical of l to 3 inclusive carbon atoms, whereby an improved concrete is obtained.

Table VIII Scaling ratings (after) Wt. Percent specified No. of cycles Material percent Air Darex AEA .033 4.2 3+ 3+ 3+ mmonnmmomhsnoH1): .5 2.8 2 2 2 2 HzC=C(CH1)COO(CH2)sSi(OCHs)a.-- .3 17 1 1 1 1 H1O CHCHQO(OHI)ISX(OCH3)5--. .3 .3 2 2 3 3 'Darex AEA .133 5.2 4+ 4+ 4 4 'HzN(CHz):NH(GH2)aSi(OCH1): .2 3.1 1 1 1 1 sodium chloride solution used.

EXAMPLE 14 2. The method of claim 1 in which an air entraining The concrete employed in this example was prepared agent is also mcorporatcfd p Q in the Same manner as the concrete of Example 13 3. The method of claim 1 in which Z is a hydrocarbon cept that 24.8 pounds of cement, 87.1 pounds of aggregroupgate, 64.6 pounds of sand and about 13 pounds of water were used The scaling ratings of tests run on this concrete are set forth in the following table.

4. The method of claim 3 in which an air entraining agent is also incorporated in the concrete mix.

5. A method which comprises incorporating in a con- T able IX Scaling ratings (after) W 1:. Percent specified No. of cycles Material percent Air Gone.

EXAMPLE 15 crete mix from 0.05 to 3 percent by weight based on the weight of the Portland cement in the concrete of a silane of the formula RSi(OR) wherein R is selected from the group consisting of phenyl and aliphatic hydrocarbon radicals of from 1 to 18 inclusive carbon atoms and R is selected from the group consisting of alkyl radicals of from 1 to 3 inclusive carbon atoms, CH CH OCH and 1 CH CH OH, whereby an improved concrete is obtained.

6. A method which comprises incorporating in a concrete mix from 0.05 to 3 percent by weight based on the weight of the Portland cement in the concrete of methyltrimethoxysilane, whereby an improved concrete is obtained.

7. A method which comprises incorporating in a concrete mix from 0.05 to 3 percent by weight based on the weight of the Portland cement in the concrete of a silane of the formula R" Si(OCI-l wherein R is an aliphatic hydrocarbon radical of 2 carbon atoms, whereby an improved concrete is obtained.

8. A method which comprises incorporating in a concrete mix from 0.05 to 1 percent by weight based on the weight of the Portland cement in the concrete of a silane of the formula R""Si(OCH where R is an aliphatic hydrocarbon radical of 3 carbon atoms, whereby an improved concrete is obtained.

9. A method which comprises incorporating in a concrete mix from 0.05 to 3 percent by weight based on the weight of Portland cement in the concrete of a silane of the formula MSi(OCH wherein M is an aliphatic hydrocarbon radical of from 4 to 18 inclusive carbon atoms, whereby an improved concrete is obtained.

10. A method which comprises incorporating in a concrete mix from 0.05 to 0.75 percent by weight based on the weight of the Portland cement in the concrete of phenyltrimethoxysilane, whereby an improved concrete is obtained.

11. The method of claim 6 in which an air entraining agent is also incorporated in the concrete mix.

12. The method of claim 1 in which Z is a substituted hydrocarbon group.

13. The method of claim 12 in which an air entrainingagent is also incorporated in the concrete mix.

14. The method of claim 12 wherein Z is an aminosubstituted hydrocarbon group.

15. An improved concrete having admixed therewith from 0.05 to 3 percent by weight based on the weight of Portland cement in the concrete of a silane of the formula ZSi(OR') wherein Z is a member selected from the group consisting of hydrocarbon groups and substituted hydrocarbon groups in which the substituent is bonded to the silicon atom through at least one carbon atom, and R is selected from the group consisting of alkyl radicals of from 1 to 3 inclusive carbon atoms, CH CH OR' and CH CH OH in which R' is an aliphatic hydrocarbon radical of 1 to 3 inclusive carbon atoms.

16. The improved concrete of claim 15 which also has an air entraining agent admixed therewith.

17. The improved concrete of claim 15 in which Z is a hydrocarbon group.

18. The improved concrete of claim 17 which also has an air entraining agent admixed therewith.

19. The improved concrete of claim 15 in which Z is a substituted hydrocarbon group.

20. The improved concrete of claim 19 which also has an air entraining agent admixed therewith.

21. The improved concrete of claim 19 wherein Z is an amino-substituted hydrocarbon group.

22. An improved concrete having admixed therewith from 0.05 to 3 percent by weight based on the weight of Portland cement in the concrete of a silane of the formula RSi(OR) wherein R is selected from the group consisting of phenyl and aliphatic hydrocarbon radicals of from 1 to 18 inclusive carbon atoms and R' is selected from the group consisting of alkyl radicals of from 1 to 3 carbon atoms, CH CH OCH and --CH CH OH.

23. An improved concrete having admixed therewith from 0.05 to 3 percent by weight based on the weight of the Portland cement in the concrete of methyltrimethoxysilane.

24. An improved concrete having admixed therewith from 0.05 to 3 percent by weight based on the weight of the Portland cement in the concrete of a. silane of the 16 formula R"Si(OCH wherein R" is an aliphatic hydrocarbon radical of 2 carbon atoms.

25. An improved concrete having admixed therewith from 0.05 to 1 percent by weight based on the weight of the Portland cement in the concrete of a silane of the formula R""Si(OCH wherein R' is an aliphatic hydrocarbon radical of 3 carbon atoms.

26. An improved concrete having admixed therewith from 0.05 to 3 percent by weight based on the weight of the Portland cement in the concrete of a silane of the formula MSi(OCH wherein M is an aliphatic hydrocarbon radical of from 4 to 18 inclusive carbon atoms.

27. An improved concrete having admixed therewith from 0.05 to 0.75 percent by weight based on the weight of Portland cement in the concrete of phenyltrimethoxysilane.

28. The improved concrete of claim 27 which also has an air entraining agent admixed therewith.

29. A method which comprises incorporating in a concrete mix from 0.05 to 3% by weight based on the weight of the Portland cement in the concrete of a silane of the formula H NCH CH NHCH CH CH Si(OCH wherean improved concrete is obtained.

30. The method of claim 29 in which an air entraining agent is also incorporated in the concrete mix.

31. A method which comprises incorporating in a concrete mix from 0.05 to 3% by weight based on the weight of the Portland cement in the concrete of a silane of the formula H NCH CH NHCH CH (CH CH Si (OCH whereby an improved concrete is obtained.

32. The method of claim 31 in which an air entraining agent is also incorporated in the concrete mix.

33. A method which comprises incorporating in a concrete mix from 0.05 to 3% by weight based on the weight of the Portland cement in the concrete of a silane of the formula H NCH CH CH Si(OC H whereby an improved concrete is obtained.

34. A method which comprises incorporating in a concrete mix from 0.05 to 3% by weight based on the weight of the Portland cement in the concrete of a silane of the formula ClCH CH CH Si(OR) wherein R is selected from the group consisting of alkyl radicals of from 1 to 3 inclusive carbon atoms, -CH CH OCH and CH CH 0H, whereby an improved concrete is obtained.

35. A method which comprises incorporating in a concrete mix from 0.05 to 3% by weight based on the weight of the Portland cement in the concrete of a silane of the formula CF CH CH Si(OR') wherein R is selected from the group consisting of alkyl radicals of from 1 to 3 inclusive carbon atoms, CH CH OCHS and CH CH OI-I, whereby an improved concrete is obtained.

36. A method which comprises incorporating in a concrete mix from 0.05 to 3% by weight based on the weight of the Portland cement in the concrete of a silane of the formula Cl C H Si(OR') wherein R is selected from the group consisting of alkyl radicals of from 1 to 3 inclusive carbon atoms, CH CH OCHS and -CH CH OH, whereby an improved concrete is obtained.

37. A method which comprises incorporating in a concrete mix from 0.05 to 3% by weight based on the weight of the Portland cement in the concrete of a silane of the formula NCCH CH Si(OR) wherein R is selected from the group consisting of alkyl radicals of from 1 to 3 inclusive, carbon atoms, CH CH OCH and -CH CH OH, whereby an improved concrete is ob tained.

38. A method which comprises incorporating in a concrete mix from 0.05 to 3% by weight based on the weight of the Portland cement in the concrete of a silane of the formula (CH NCH CH CH Si(OR) wherein R is selected from the group consisting of alkyl radicals of from 1 to 3 inclusive carbon atoms, -CH CH OCH 17 and CH CH OH, whereby an improved concrete is obtained.

39. A method which comprises incorporating in a concrete mix from 0.05 to 3% by weight based on the weight of the Portland cement in the concrete of a silane of the formula nog-cmcmcmsuorm wherein R is selected from the group consisting of alkyl radicals of from 1 to 3 inclusive carbon atoms, --CH CH OCH and CHZCH2OH, whereby an improved concrete is obtained.

40. A method which comprises incorporating in a concrete mix from 0.05 to 3% by weight based on the weight of the Portland cement in the concrete of a silane of the formula CH =C(CH )COOCH CH CH Si (OR') wherein R is selected from the group consisting of alkyl radicals of from 1 to 3 inclusive carbon atoms, -CH CH OCH and -CH CH OH, whereby an improved concrete is obtained.

41. A method which comprises incorporating in a concrete mix from 0.05 to 3% by weight based on the weight of the Portland cement in the concrete of a silane of the formula c nknomo'cmcmcmsuon' a wherein R' is selected from the group consisting of alkyl radicals of from 1 to 3 inclusive carbon atoms, CH CH OCH and -CH CH OH, whereby an improved concrete is obtained.

42. An improved concrete having admixed therewith from 0.05 to 3% by weight based on the weight of Portland cement in the concrete of a silane of the formula H NCI-I CI-l NHCH CH CH Si(OCH 43. The improved concrete of'claim 42 which also has an air entraining agent admixed therewith.

44. An improved concrete having admixed therewith from 0.05 to 3% by weight based on the weight of Portland cement in the concrete of a silane of the formula H NCH CH NHCH CH (CH CHgSl OCH 45. The improved concrete of claim 44 which also has an air entraining agent admixed therewith.

46. An improved concrete having admixed therewith from 0.05 to 3% by weight based on the weight of Portland cement in the concrete of a silane of the formula H NCH CH CH Si,OC H

47. An improved concrete having admixed therewith from 0.05 to 3% by weight based on the weight of Portland cement in the concrete of a silane of the formula ClCH CH CI-I Si(OR') wherein R is selected from the group consisting of alkyl radicals of from 1 to 3 inclu sive carbon atoms, CH CH OCH and -CH CH OI-I.

48. An improved concrete having admixed therewith from 0.05 to 3% by weight based on the weight of Portland cement in the concrete of a silane of the formula CF CH CH Si(OR') wherein R is selected from the group consisting of alkyl radicals of from 1 to 3 inclusive carbon atoms, -CH CH OCH and -CH CH OH.

49. An improved concrete having admixed therewith from 0.05 to 3% by weight based on the weight of Portland cement in the concrete of a silane of the formula Cl C H Si(OR') wherein R is selected from the group consisting of alkyl radicals of from 1 to 3 inclusive carbon atoms, --CH CH OCH and CH CH OH.

50. An improved concrete having admixed therewith from 0.05 to 3% by weight based on the weight of Portland cement in the concrete of a silane of the formula NCCH CH Si(OR') wherein R is selected from the group consisting of alkyl radicals of from 1 to 3 inclusive carbon atoms, ---CH CH OCH and CH CH OH.

51. An improved concrete having admixed therewith from 0.05 to 3% by weight based on the weight of Portland cement in the concrete of a silane of the formula (CH NCH CH CH Si(OR') wherein R is selected from the group consisting of alkyl radicals of from 1 to 3 inclusive carbon atoms, CH CH OCH and -CH CH OH.

52. An improved concrete having admixed therewith from 0.05 to 3% by weight based on the weight of Portland cement in the concrete of a silane of the formula HoOcmcmomsuoR' wherein R' is selected from the group consisting of alkyl radicals of from 1 to 3 inclusive carbon atoms, -CH CH OCH and CH CH OH.

53. An improved concrete having admixed therewith from 0.05 to 3% by weight based on the weight of Portland cement in the concrete of a silane of the formula CH =C(CI-I )CO0CH CH CH Si(OR') wherein R is selected from the group consisting of alkyl radicals of from 1 to 3 inclusive carbon atoms, CH CH OCH and CHZCHZOH.

54. An improved concrete having admixed therewith from 0.05 to 3% by weight based on the weight of Portland cement in the concrete of a silane of the formula wherein R' is selected from the group consisting of alkyl radicals of from 1 to 3 inclusive carbon atoms, CHZCHZOCH3 and -CH CH OH.

References Cited by the Examiner UNITED STATES PATENTS 2,491,487 12/49 Faulwetter 106-90 FOREIGN PATENTS 1,207,978 9/59 France.

OTHER REFERENCES McGregor: Silicone and Their Uses, McGraw-Hill, v

1954, pages 267-279.

Meals et al.: Silicones, Reinhold Publication Corporation, New York, 1959, page 108.

TOBIAS E. LEVOW, Primary Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,190,762 June 22, 1965 Barber C. Carlson et al.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 8, line 38, for "CH =CHSI(OCH read CH =CHSi(OCH column 11, line 60, for "(C H 0) Si[CH )CN" read (C H O) Si(CH CN column 16, line 22, for "where" read whereby lines 51 and 59, for "-CH CH 0CHS each occurrence, read -CH CH OCH column 17, line 48, for

"H NCH CH CH Si ,OC H read H NCH CH CH Si(OC H Signed and sealed this 29th day of March 1966.

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Attesting Officer Commissioner of Patents 

1. A METHOD WHICH COMPRISES INCORPORATING IN A CONCRETE MIX FROM 0.05 TO 3 PERCENT BY WEIGHT BASED ON THE WEIGHT OF THE PORTLAND CEMENT IN THE CONCRETE OF A SILANE OF THE FORMULA ZSI(OR'')3, WHEREIN Z IS A MEMBER SELECTED FROM THE GROUP CONSISTING OF HYDROCARBON GROUPS AND SUBSTITUTED HYDROCARBON GROUPS IN WHICH THE SUBSTITUENT IS BONDED TO THE SILICON ATOM THROUGH AT LEAST ONE CARBON ATOM, AND R'' IS SELECTED FROM THE GROUP CONSISTING OF ALKYL RADICALS OF FROM 1 TO 3 INCLUSIVE CARBON ATOMS, -CH2CH2OR'''''' AND -CH2CH2OH WHERE R''" IS AN ALIPHATIC HYDROCARBON RADICAL OF 1 TO 3 INCLUSIVE CARBON ATOMS, WHEREBY AN IMPROVED CONCRETE IS OBTAINED. 